Expansible pulley.



E. R. BLING.,

EXPANSIBLE PULLEY. APPLICATION man MAR. ze. Isis.

.1 ,299',669. Patented ApnS, 1919.

INVENTOR ggf" l WITNESSES 4 BY lr/IAV um .L

ATTO R N EY UNITED EDGAR R. BOLINGr, 0F HANNIBAL, MISSOURI.

EXPANSIBLE PULLEY.

Specification of Letters Patent.

Patented Apr. 8, 1919.

Application filed March 26, 1918. Serial No. 224,781.

To all whom it may cof/wcm:

lBe it known that I, EDGAR R. BoLiNc, a citizen of the United States,residing at Hannibal, in the county of Marion and State Vof Missouri,have invented certain new and useful Improvements in Expansible Pulleys,of which the foregoing is a specifica tion.

In the operation of milling and agricultural machinery, it yisfrequently necessary l to adjust the drive belt in order to prevent n Itis not always convenient to compensate for slack by shortening the belt,hence the desirability of providing other means for taking up slack inthe belt to-in slipping.

sure positive engagementA betweenI it and the coperating pulleys.

In accordance with the present invention, a pulley is provided which maybe enlarged diametrically so as to compensate for slack in the drivebelt when the same occurs. Moreover, by providing an expansible pulleythe diameter of the samemay be reduced or enlarged to meet existingconditions, because at times the drive belt may contract, therebynecessitating a reduction in the diameter of the pulley in order toprevent straining of the parts and also to enable the drive belt beingplaced in position.

rIhe present invention contemplates a combined expansible belt pulleyand clutch whereby the pulley may be thrown into or out of action andexpanded or contracted to meet varying conditions as may be foundnecessary.

The drawing illustrates a preferred embodiment of the invention,however, it is to be understood that in adapting the same to meetdifferent conditions, various changes in the form, proportion, and minordetails of construction may be resorted to without departing from thenature of the invention as claimed hereinafter.

In the drawings:

Figure 1 is a central longitudinal section of an expansible pulleyembodying the invention, the tread sections and their connectionsintermediate the top and the bottom tread sections being omitted.

Fig. 2 is an end view thereof.

Corresponding and like parts are referred to in the followingdescription and indicated in both views of the drawings by likereference characters.

The pulley is mounted on a shaft 1 on which is secured a member 2 and aclutch element 3. A hand wheel 4L is also secured on the shaft 1 andconstitutes means whereby the shaft may be rotated under certainconditions to admit of the diameter of the pulley being varied.

The pulley comprises a relatively fixed inner portion and an outerexpansible portion. vThe inner portionis loose on the shaft 1 and isadapted to be clutched thereto. The outer portion is expansible andcomprises two members 5 and 6 which are internally screw threaded tomatch corresponding threaded portions7 and'S of the shaft. The parts 7and 8 are oppositely threaded, z'. e., one of such `threads is righthand and the other left hand. Rotation of the shaft 1 in one directionwill cause the members 5 and 6 to move toward each other, therebyresulting in expanding the pulley. Rotation of the shaft 1 in a reversedirection effects movement of the members 5 and 6 away from each other,thereby contracting the diameter of the pulley. The rim of the pulleycomprises a plurality of sections 9, and links 10 and 11 connectingopposite end portions of the sections with the members 5 and 6. Theselinks cross each other and are pivotally connected at their outer endsto the sections 9 and are similarly connected at their inner ends to themembers 5 and 6. The threads 7 and 8 being of like pitch effect auniform movement of the members 5 and 6 with the result that theelements 9 always remain parallel at all stages of their adjustment.

The inner portion of the pulley comprises end pieces 12 and 13 anddrive-rods 14, the latter extending parallel with the shaft 1 and havingtheir ends connected in any manner to the respective parts 12 and 13.The links 10 and 11 extend across the path of the ties 14, hence bothparts of the pulley are caused to rotate when the shaft 1 is in active voperation. The central portion of the pulley is mounted loosely upon theshaft 1 and is provided at one end with aclutch element 15 which isadapted to coperate with an accompanying clutch element 16 splined tothe shaft 1. When the clutch element 16 is moved outwardly so as toclear the clutch element 15, the shaft 1 may be rotated by means of thehand wheel 1 so as to vary the diameter of the pulley as may berequired. After the diameter of the pulley has been adjusted, the clutchmember 16 is moved inward to clutchingly engage the element 15,

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thereby clutching the pulley to the shaft l whereby Aboth parts Willrotate in unison. The shaft l may be mounted in any desired manner7 andthe clutches 15 andAlG may-'be of any type so long as it suffices toengage thepulley With the shaft. A clutch member 17 is disposed at theopposite end of the central portion of the pulleyand Coperates with theclutch element 3 to clutchingly engage the pulley With'the part 2 Whenthe latter is to be rotated.

W'hat I claim is:

l. An 'expansible pulley, comprising a shaft having portions reverselythreaded, a

pulley mounted on saidy shaft and comprising inner and outer portions,the inner portion consisting of spaced members connected'by Vties landthe outer portion comprising elements mounted upon the reverselythreaded portions 'of the shaft, pulley rim sections, .and links`connecting the pulley rim sections With the members engaging thereversely threaded portions of the shaft, said-elinkscrossing andextending across the path of the ties connecting the -spacedparts of theinner portion of the spaced members loose on the shaft, ties connectingthe spaced members, a clutch connecting one of said spaced-members `tothe shaft, other members mounted uponthe reverselyithreaded portions `ofthe shaft," pulley rim sections, land crossing links pivotallyconnecting the` pulley rim fsectionswith the members mounted yupon( the'reversely threaded portions of the shaft.

In testimony whereof I aiiiX my signature inpresence of tWo Witnesses.

l EDGARR; fBOLING.

Vitnesses C. BOLING, T. 'AjBoLINa Copies of this patent may be obtainedfor' five 'cents' each,' bylddressinglthe "Cmmissioneriof Patents,

v Washington; l). C.

